Lenny is making his own laundry soap. The recipe calls for 2 parts borax, 2 parts washing soda, and 1 part soap flakes it Lenny uses 7 cups of soap flakes, how many cups of borax and washing soda combined does he need? (1 point)
Since the recipe calls for 1 part soap flakes, and Lenny is using 7 cups of soap flakes, the total number of parts in the recipe is 2 + 2 + 1 = 5 parts.
To find the total number of cups of borax and washing soda combined, we need to find the number of parts that represent 7 cups of soap flakes.
Each part represents 7/1 = <<7/1=7>>7 cups of soap flakes.
Therefore, Lenny needs 2 parts of borax, which is 2 * 7 = <<2*7=14>>14 cups of borax.
And he needs 2 parts of washing soda, which is 2 * 7 = <<2*7=14>>14 cups of washing soda.
Therefore, Lenny needs a total of 14 + 14 = <<14+14=28>>28 cups of borax and washing soda combined. Answer: \boxed{28}.
To find the number of cups of borax and washing soda combined that Lenny needs, we first need to determine the ratio of ingredients in the laundry soap recipe.
The recipe calls for 2 parts borax, 2 parts washing soda, and 1 part soap flakes. This means that for every 2 cups of borax and washing soda, Lenny needs 1 cup of soap flakes.
Since Lenny is using 7 cups of soap flakes, we can set up an equation to find the amount of borax and washing soda needed:
(2 cups of borax and washing soda) / (1 cup of soap flakes) = (x cups of borax and washing soda) / (7 cups of soap flakes)
Cross-multiplying the equation, we get:
2 cups of borax and washing soda = (x cups of borax and washing soda) * 7 cups of soap flakes/1 cup of soap flakes
Simplifying the equation:
2 cups = 7x
Dividing both sides of the equation by 7:
2 cups / 7 = x
So Lenny needs approximately 0.286 cups of borax and washing soda combined.
Since the recipe calls for 2 parts borax, 2 parts washing soda, and 1 part soap flakes, we can add up the parts to determine the total number of parts needed.
The total number of parts needed is 2 + 2 + 1 = 5 parts.
Given that Lenny uses 7 cups of soap flakes, which represents 1 part, we can calculate the number of parts of borax and washing soda needed.
If 1 part equals 7 cups, then 5 parts equal 5 x 7 = 35 cups.
Therefore, Lenny needs a total of 35 cups of borax and washing soda combined.